One common reason why this problem occurs is because it is being blocked by the firewall which is why you will need to make sure that it is given firewall access. Listed below are the recommended troubleshooting steps you need to do to fix this problem. There are several factors that can cause this particular problem ranging from interference from the antivirus program to a faulty mod. This will refresh the operating system as well as remove corrupt temporary data and is quite effective in fixing most software related issues.
Before performing the recommended troubleshooting steps for this particular problem I suggest that you try restarting your computer first.